The startup uses artificial-intelligence software to aggregate raw 3-D data from sensors on self-driving cars to create highly detailed maps used to direct autonomous vehicles. Civil Maps said its format uses less data, reducing the cost of transmission over cellular networks. That lets the technology provide more real-time road data gathered through crowd-sourcing traffic information from other cars.

"Investing in and working with Civil Maps gives us an additional way to develop 3-D high-resolution maps, which will bring fully autonomous Ford vehicles a step closer for consumers," said Alan Hall, a spokesman for the automaker.Ford has been making modest bets on technology partners as it researches self-driving cars and the sharing economy. In May, the Dearborn, Michigan-based automaker invested $182.2 million to take a stake of about 6.6 percent in Pivotal Software Inc., a cloud-computing company that helped it develop a mobility app.

Other automakers are also making similar moves. General Motors Co. spent nearly $1 billion acquiring self-driving software maker Cruise Automation and invested $500 million for a 9 percent stake in ride-hailing company Lyft Inc. Fiat Chrysler Automobiles NV has teamed with Alphabet Inc.'s Google to develop 100 self-driving minivans.